Extraction never came. The lamps are dying, the magazines are short, and the corridor outside Block 7 is moving. Hold the block, feed the horde lead, and stay breathing until the sun does the work for you.
Slow, dumb, endless. Centre mass, keep moving.
Fast and fragile. Kills you if you stop to reload.
Armoured wall. Use barrels, shotguns, penetration.
Keeps range and throws acid. Close the gap.
Arrives every fifth wave. It charges. Dodge it.